Method and machine for grinding tapered rollers



Feb. l5, 1944. A. R. sPlcAccl 2,341,825

METHOD AND MACHINE I'OR GRINDING' TAPRED ROLLERS Filed June 6. 1941 2 Sheets-Sheet 2 /-//5 ATTORNEY' Patented Feb. 15,1944

METHOD AND MACHINE FOR GRINDING I TAPERED ROLLERS Attilio R. spictei, Blainville conn., assigner to General Motors Corporation, Detroit, Mich., a corporation of Delawarey Application June 6, 1941, Serial No. 396,906

- 1s claims.,A

' This invention relates toY a method 3f/,Vanda machine for grinding tapered rollers.

An object is to provide an eiiicient'an'd simple grinding method and a machine of the centerless" type for grinding taperedv rollers to a predetermined size. A further object is'toprovide a grinding machine in which blanks to be ground may be continuously and successivelyfed in at one side of the machine,A automatically ground to thev required `size and taper, and thereafter dis- .ehargd'at the other side of the machine.

, -To these endsl and also to improve generally' upon-devices of the character indicated, the lnvention consists in the various matters hereinafter described and claimed. In its broader aspects the-invention` is not necessarily limited to vthe specific constructions vselected for illustrative purposes/inthe'accompanying drawings in which Figure" 1 is a fragmentary .view-,with parts broken away in lcngitudinaldi'ametrlcal section to better illustrateth invention; Figure 2 isa View taken substantially along the line 2--2 of Figure 1 and looking in the direction A of the arrows; and

Figure 3 is a fragmentary view taken generally along the-line 3-3 of Figure 2. Generally stated, the invention comprises a method of and machine of the centerlesstype for' grinding tapered rollers .to a predetermined size. Roller blanks W, fed-from a chute, are guided by a carrier, as therotatable work receiving cage IU, alongacurved path in rolling-.and peripherally ground engagement between the frusto-conical face of. a rotated regulating wheel II and the flat grinding` face of a grinding wheel I2. work feeding shoe or cam I3 engages the outer 'end of each roller during grinding and gradually feeds each roller endwise and radially inwardly of the regulating wheel II through a predetermined .extentduring the grinding cycle thereby causing the rollers to be fed up the incline of the regulating wheeland laterally into the grinding wheel I2 so that the rollers will successively emerge from the grinding zone finished to the precisely required size and taper. r

Referring to the illustrated embodiment of this invention, a suitable grinding machine base I5 is provided with ways I1 upon which is slidably mounted a bracket I8 having a bearing I9 rotatably receiving a grinding wheel shaft 22 which is also rotatably and slidably lournalled in a bracket 23 secured to the base I5 as by the cap screws 24. The rotatable grinding wheel I2, which has a at grinding face 25 perpendicular to the axis of grinding wheel rotation, is fastened Within a wheel flange 26 that is rigidly and demountably secured as by cap screws to a hub 21 secured to the shaft 22 as by a key and engaged by a thrust washer 28 abutting the end of the bearing A I9 on the movable bracket I8. A feed screw 29 manually operated by a crank 30, is journa-lled in and secured against endwise movement in the bracket 23. vThis feed screw 29 is threaded within the bracket- I8 so that a rotation of the crank 10 30 will serve to initially position the grinding ,Y ;whee1 and to occasionally advance the grinding The grinding wheel. to compensate for wear. )wheel may be rotated in any suitable manner, as

by a belt 32 running' over a pulley 33 keyed to.

the work receiving cage I0 and the regulatingl wheel l I. A bearing 36 at the end of the bracket v nearest the grinding wheel rotatably receives a sleeve 31 to the end of which is detachably keyed the regulating wheel II that has a frusto-conical work engaging face 38 in opposed spaced relation to ther grinding wheel I2. The regulating Wheel I I is interchangeable with generally similar'regulating Wheels but of different taper, and the elements of revolution which geometricaly define the frusto-conical regulating wheel face 38 are so angularly disposed to the plane of the grinding wheel face as to determine the required angle of taper of each of the finish ground rollers W and to cause the roller peripheries to be properly ground at this required angle of taper by the flat grinding wheel face 25. As shown in Fig. 1, the axis of the grinding wheel I2 lies parallel to but is preferably laterally oiset from the common axis of the regulating wheel I I and the work cage I0 sufiiciently so that the rollers W will move upon the grinding wheel face 25 during the grinding cycle and tend to maintain the grinding wheel face 25 in a. trued condition. Axial thrust of the regulating wheel II is received by a thrust washer-'39 Vlocated between the bearing 36 and a.` hub on the regulating Wheel I I. The regulating wheel may be suitably rotated as by a belt A42v running on a pulley 43 keyed to the sleeve 31.

To assure that the regulating wheel II runs true on its axisand to aid in the rotatable support of the work cage I0, the sleeve 31 is much longer than the bearing 36 and is preferably provided with a bushing 44 that rotatably receives a work cage shaft 45 having a work cage supporting head 46 at its inner end and a reduced outer end 41 which is rotatably supported by an antifrlction bearing 48 mounted in a housing 50 that forms part of the bracket 34. This bearing 48, which may be of various constructions, is illustrated as a conventional ball bearing having inner and outer race rings respectively secured to the shaft reduction 41 and to the housing 50 and adapted to carry both radial and thrust loads so that the shaft 45 is axially positioned. The work cage I is suitably rotated as by a belt 5I running over a pulley 53 keyed to the shaft 45, and spacer washers 54 and 55 respectively located between the pulley 53 and the bearing 48 and between the pulley 53 and the rotatable sleeve 31 co-operate with the thrust washer 39 in preventing axial movement of the sleeve 31 and the regulating wheel I I.

The work cage I0, which is in the form of a disc coaxial with the regulating wheel Il, is rotatably carried by the shaft 45 in spaced relation between the regulating Wheel and the grinding wheel. A central work cage recess 56 slidablyfits over the head 46, and cap screws 51 demountably and rigidly fasten the cage I0 to the head 46 so that similar work cages adapted for receiving other sized rollers may be easily interchanged therewith. As shown in Fig. 2, the cage l0 has a multiplicity of peripherally spaced substantially radially inwardly extending pockets 58 each of which is open at the cage periphery to receive a roller blank W endwise from an inclined work chute 60 in the top of an upstanding arm 6I of the bracket 34 and in which the roller blanks are mounted in end to end relation with their smaller ends directed towards the cage I0. When the cage I0 is rotated as indicated by the arrow, these roller blanks will gravitate towards the cage, and the lowermost rollers will be picked up successively by the pockets 58 and carried through the grinding zone. Each pocket 58 has a radial length that exceeds the length of the roller W received therein, and each pocket has a pair of opposed converging straight sided walls 62 and 63 so spaced that a roller cannot wedge therebetween. These walls are of such angular rela tion that a roller in laterally guided engagement with either of these walls will have its axis located substantially radially of the regulating wheel Il.

The work feeding shoe I3, which comprises an arcuately shaped member overlying and spaced from the upper portion of the work cage Ill in spaced relation between the grinding wheel I2 and the regulating wheel Il, is demountably fastened, as by screws 64, in seats 55 at the ends of arms 66 extending from the bracket 34. The shoe I3 has a substantially arcuate inner cam face 51 that gradually approaches the axis of the regulating wheel II from the loading position L at the end of the chute 60 to the discharge position D at the other end of the shoe where the nish ground rollers W are free to drop from the pockets 58 into a suitable bin (not shown). The

outer ends of the rollers are engaged by this cam face 61 as shown in Fig. 2, and as these rollers W are advanced through the grinding zone by the work cage I0 they are gradually axially pushed inwardly towards the axis of the work engaging plate, and the frusto-conical face 38 laterally feeds these rollers through a controlled extent into the grinding wheel thereby resulting in finish ground rollers of predetermined size and taper. The entrance end of the shoe I3 is rounded at68 to facilitate gradual engagement of the successive rollers W with the cam face 61 at the start of each roller feed and the extent of roller feed may be controlled by employing interchangeable shoes I3 of desired internal roller engaging face curvatures. Also, the final diameter of the ground rollers may be predetermined by manually operating the crank 30 to preset the distance between the grinding and regulating wheels.

This machine operates as a centerless type of grinding machine wherein the grinding wheel I2 is rotated at a fast surface speed to produce the required grinding action, and the frusto-conical regulating wheel Il rotates in the same direction and at a lower surface speed to uniformly turn the rollers W during grinding, and the work cage I0 turns at a very slow rate as compared to the regulating wheel and controls the length of the grinding cycle between the loading station L and the discharge station D.

I claim:

l. The method of grinding the periphery of a tapered roller at a predetermined angle of taper between a rotated grinding wheel and a rotated regulating wheel, comprising the steps of inserting the roller substantially radially of and between both wheels, traversing the roller against the grinding wheel while maintaining said roller in rolling contact with the regulating wheel, feeding the roller endwise towards the axis of rotation of the regulating wheel, and continuously feeding the roller laterally through a predetermined extent at a controlled rate towards said grinding wheel during the entire rolling contact of said roller against the regulating wheel.

2. The method of grinding the periphery of a tapered roller at a predetermined angle of taper between a rotated grinding wheel and a rotated regulating wheel, comprising the steps of inserting the roller substantially radially of and between both wheels, traversing the roller against the grinding wheel and in rolling contact with the regulating Wheel along a predetermined path and at a controlled rate which is independent of the rates of rotation of said grinding wheel and said regulating wheel, feeding the roller endwise towards the axis of rotation of the regulating wheel during said entire rolling contact, and simultaneously feeding the roller laterally into the grinding Wheel.

3. The method of grinding the peripheral surface of a conical roller between the conical face of a rotated regulating wheel andthe opposed flat face of a rotated grinding wheel, comprising the steps of laterally traversing the roller between and in engagement with said wheel faces, maintaining the roller substantially radially of both wheels throughout the lateral traverse, and simultaneously feeding the roller endwise towards the axes of rotation of both of said wheels and laterally towards said grinding wheel face during the entire movement of said roller in' engagement with said regulating wheel.

4. The method of grinding the peripheral surface of a frusto-conical roller between the conical face of a rotated regulating wheel and the opposed flat face of a rotated grinding wheel, comprising the steps of locating, the roller in rolling contact with said conical face, traversing the roller along a predetermined curved path against said flat grinding wheel face, maintaining the roller substantially radially of both wheelsthroughout the lateral traverse, and simultane-y ously feeding the roller through a predetermined extent at a predetermined rate both towards the axis of rotation of said regulating wheel and towards said flat grinding wheel face during thev entire movement of said roller in rolling contact with said conical face. v

radially of said conical "face andthrough a pre-"A determined' extent duringv said traverse.

6. In a device of ther character indicated, a rotatable grinding wheel having a flat grinding face, a rotatable regulating wheel for peripherally and rotatably engaging a work piece, a work cage to traverse,I a work piece against the said grinding wheel face while maintaining the work piece in rolling engagement with said regulating wheel, and means gradually feeding said work piece radially inwardly of the regulating wheel and laterally -towards said grinding wheel through a predetermined extent during said traversing movement.

'7. In a centerless grinding machine for peripherally grinding tapered rollers, a rotatable grinding wheel having a flat grinding face, a rotatable regulating wheel having a conical roller engaging face opposed in spaced relation to said grinding face, a roller receiving cage rotatable between the grinding and regulating wheels and arranged to traverse a roller on said at grinding wheel face while positioning the roller in rolling engagement with said conical face, and feeding means independent of both the cage and the regulating wheel for feeding a cage guided roller into the grinding wheel through a predetermined extent.

8. In a centerless grinding machine for grinding rollers, a rotatable grinding wheel, a rotatable regulating wheel, a roller receiving cage rotatable between the grinding wheel and said regulating wheel, said cage being provided with peripherally spaced radially disposed pockets having open ends at said cage periphery, means for loading successive rollers endwise into successive pockets during said cage rotation, said cage traversing the rollers against the grinding wheel, and means engaging the outer ends of said rollers beyond said pockets and gradually feeding each of said rollers endwise and radially inwardly of said cage through a predetermined extent during said cage rotation.

9. In a device of the character indicated, a rotatable grinding wheel having a fiat grinding face, a rotatable regulating wheel having a conical work engaging face opposed to and spaced from said at grinding face, arotatable work receiving cage for advancing the work between said regulating wheel and said grinding wheel, and a work feeding shoe overlying said work receiving cage in spaced relation and arranged to feed a work piece endwise up said corneal face as the work piece is advanced.

10. In adevlce of the character indicated, a rotatable grinding wheel having a flat grinding face, a rotatable regulating Wheel having a conical work engaging face opposed to and spaced from said fiat grinding face, a rotatable work receiving cage coaxial with -the regulating wheel andlocated between said regulating and grinding wheels,A a Workfeeding shoe peripherally overlying a portion of' said cage in spaced relation,

and an arcuate cam face on said work feeding shoe eccentric to said regulating wheel.

11. yIn a centerless grinding machine for peripherally grinding tapered rollers, a rotatable grinding wheel having a nat grinding face, a

rotatable regulating wheel having a conical roller engaging face opposed to and spaced from said fiat grinding wheel face, a rotatable work cage having a roller receiving pocket for traversing a roller upon said iiat grinding wheel face and in rolling contact with said regulating wheel face, a work engaging shoe, and a curved face on said shoe'which engages an end of said roller and feeds the roller 'inwardly' of the conical face through a predetermined extent during the entire traverse of the roller against said regulating wheeLq l2. In a centerless grinding machine for tapered rollers, a rotatable grinding wheel having a flat grinding face, a regulating wheel having a conical roller engaging face opposed to and spaced from said flat grinding face, said regulating wheel being rotatable about an axis parallel to but laterally offset from the axis of grinding wheel rotation, a rotatable work cage coaxial with said regulating wheel and located between the regulating and grinding wheels, the Work cage having peripherally spaced pockets for receiving and traversing rollers successively against said flat grinding wheel face While maintaining the rollers in rolling engagement with the conical regulating wheel face, and feeding means for uniformly moving the rollers into the rotatable regulating wheel having a conical roller engaging face opposed to and spaced from said fiat grinding wheel face, a rotatable work cage between said regulating and grinding wheels and having peripherally spaced roller receiving pockets opening radially inwardly of said cage, said cage rotation serving to traverse the rollers in said pockets across the iiat grinding wheel face while maintaining the rollers in rolling engagement with said conical regulating wheel face, means sequentially delivering rollers endwise into successive cage pockets during the cage rotation, a work feeding shoe, and a curved face on said shoe engaging the ends of said rollers beyond the cage and gradually feeding said rollers radially inwardly of said conical face through a predetermined extent during the traverse of the rollers across the grinding wheel.

14. In a centerless grinding machine for tapered rollers, a rotatable grinding wheel having a flat grinding face, a rotatable regulating Wheel having a conical roller engaging face opposed to and spaced from said fiat grinding wheel face, a rotatable work cage between said grinding and .regulating wheels, said work cagehaving peripherally disposed roller receiving pocketsI opening onto the cage periphery, an inclined chute supporting rollers in end to end relation and arranged to slidably deliver successive rollers into successive pockets during the work cage rotation, an arcuate Work feeding shoe overlying the upper portion of the work cage periphery, andan inner cam face on the work,feeding shoe which engages the outer ends of the rollers and gradually feeds vthe rollersendwise through a4 predetermined extent. f l

l5. The method of centerless grinding the peripheral surfaces of tapered rollers in the throat between the converging faces of a regulating wheel and a grinding wheel, comprising the steps -of successively inserting the rollers between and in contact. with both wheels for a sidewise rolling traverse substantially circumferentially ot both wheels and for substantially the same angular extent of traversing contact along both Wheels, positively controlling the rate of said traverse independently of the speed of rotation of the wheelsfshifting the rollers endwise during said traverse at a uniform .controlled lrate to control a uniform lateral feedoff'th'e rollers against the grinding wh/'eelg--andsuccessively discharging the rollers/'from between the wheels after their travfr ""e'r'se therebetween.

16.' The method of centerless grinding the peripheral surfaces of tapered rollers in the throat between' the convergingviaces of a regulating wheel and a grinding'wheel, comprising the steps of successivei inserting the rollers between and in contact with both Wheels for a sidewise rolling traverse along both wheels, positively controlling the rate of said traverse independentlyof the speed of rotation of the wheels, and shifting vthe rollers endwise during said traverse at a uniform controlled rate'to control a uniform lateral feed of the rollers against the grinding wheel.

17. The method of centerless grinding the peripheral surfaces of tapered rollers in the throat between the converging faces of a regulating wheel and a grinding wheel, comprising the steps of successively inserting the rollers between and in contact with both wheels for a sidewise rolling traverse substantiallyv circumferentially of both.

wheels and for substantially the same angular extent of traversing Contact along both wheels, positively shifting the rollers endwise during said traverse at a -uniform controlled rate to control auniform lateral feed of the rollers against the grinding. Wheel, and successively discharging thev rollers from contact with both wheels irrimediately after their traverse therebetween.

18. The method of centerless grinding the peripheral surfaces of tapered rollers between the converging faces of a rotary grinding member and an opposed member on whichthe rollers. roll, comprising the steps of successively inserting the rollers between and in contact with both members. 

